High capacity double-layer capacitor cells (also known as super-capacitors and ultra-capacitors) are rated for operation at low voltages. The operating cell voltages of double-layer capacitor cells are typically no more than about 4 volts and nominally about 2.7 volts. Charge storage devices are often used in combination to provide higher energy delivery and/or higher capacitance. To provide such higher energy delivery and/or higher capacitance, one or more interconnection typically needs to be made. It would be desirable that such interconnections be as simple and reliable as possible.